For many years, high dietary cholesterol was thought to lead to increases in blood cholesterol, which in turn elevated the risk of cardiovascular disease (CVD), a leading cause of death in the United States. However, extensive research to date has not yielded evidence to support the role that dietary cholesterol was thought to have had in the development of CVD. As a result, the 2015-2020 Dietary Guidelines for Americans removed the recommendations of restricting dietary cholesterol to 300 mg per day in healthy individuals. There is ample evidence, however, that saturated fatty acids and trans-fats increase CVD risk.
[Photo: Dr. Ghada Soliman]
Dr. Ghada Soliman, associate professor of nutrition in the department of environmental, occupational, and geospatial health sciences at the CUNY Graduate School of Public Health & Health Policy, has published a review of the current literature regarding dietary cholesterol, blood cholesterol, saturated fatty acids, and their relationship to cardiovascular disease.
Dr. Soliman notes that the fact that dietary cholesterol is common in foods that are high in saturated fatty acids might have contributed to the hypothesis that dietary cholesterol led to increased blood cholesterol, promoting fatty plaques in the arteries, inflammatory arterial responses, and the narrowing of arterial tubes, all symptoms of CVD.
The hypothesis that dietary cholesterol contributes to the risk of heart disease was initially suggested in 1968 based on the research data available at that time. However, follow-up studies over the years showed no association between dietary cholesterol, specifically from egg consumption, and blood cholesterol, all-cause death, or coronary heart disease. Many common foods that contain high cholesterol also tend to be rich in saturated fatty acids (SFA). Eggs are an exception, with one large egg (50 grams) containing 186 milligrams of cholesterol, and only 1.56 grams of SFA. In addition, eggs are nutrient-dense food rich in high quality animal protein and micronutrients, but low in saturated fatty acids, that is convenient and affordable to lower income families and serves as a good source of nutrients for people of all ages, including growing children.
Dr. Soliman concludes that the current body of literature does not support the concept that dietary cholesterol increases the risk of CVD in healthy individuals. However SFA, which often occur concurrently with dietary cholesterol in various foods, and trans-fats do increase LDL blood cholesterol and the risk for CVD, and thus their consumption should be monitored and reduced when possible.